Such an arrangement is known for example from DE 102 51 225 A1. With this prior art, to create a durable, in particular oil-tight, seal between a piezoactuator and an external contact arrangement, it is proposed that a fuel-resistant sealing ring (O ring) be inserted into each opening of a top plate positioned thereon. A collar made of an insulating material is also inserted below the sealing ring in each through opening, said collar ensuring the centering and electrical insulation of the terminal post.
It is a disadvantage of this known piezoactuator contact arrangement that it requires a comparatively thick top plate, in order to accommodate a sealing ring and a centering collar respectively in its through openings.
Also with this prior art a number of individual sealing components have to be used during assembly of the injector, thereby making it a comparatively complex operation.
The piezoactuator sealed with the known arrangement also has a limited useful life. It has proven that this useful life is a function of the installation environment of the fuel injector.